Geology - Sedimentary Rocks and Processes
How does diagenesis occur?
is the change of sediments or existing sedimentary rocks into a different sedimentary rock during and after rock formation (lithification), at temperatures and pressures less than that required for the formation of metamorphic rocks.
How does lithification occur?
minerals (usually quartz or calcite) grow in pore spaces by precipitating from groundwater, and burial adds pressure to sediment and squeezes air and water out from the grains
What are turbidite deposits?
the geologic deposit of a turbidity current, which is a type of sediment gravity flow responsible for distributing vast amounts of clastic sediment into the deep ocean.
How are sediments lithified?
the process by which sediments combine to form sedimentary rocks. ... With compaction, sediment grains get squished together, reducing the size of the original pore space that divided them.
How are sediments deposited?
Heavier particles fall to the bottom first, followed by smaller, lighter particles.
How are sediments buried?
As layers are piled one upon another, the sediments beneath are buried, sometimes by hundreds of metres of sediment above.
What are major sedimentary structures and how do they form?
Examples include bedding or stratification, graded bedding, and cross-bedding. Sedimentary structures that are produced shortly after deposition and as a result of compaction and desiccation are called penecontemporaneous sedimentary structures. Examples include mud cracks and load casts.
How do turbidite deposits form?
Rivers flowing into the ocean deposit sediments on the continenal shelf and slope. These slopes fail in response to excessive sedimentation load and sometimes earthquake shaking, sending the sediments sliding down to the ocean bottom to create a turbidite.
How are sedimentary rocks formed from sediments? *
Sedimentary rocks are formed when sediment is deposited out of air, ice, wind, gravity, or water flows carrying the particles in suspension.
What are common names and descriptions of sedimentary rocks? *
There are three basic types of sedimentary rocks. Clastic sedimentary rocks such as breccia, conglomerate, sandstone, siltstone, and shale are formed from mechanical weathering debris.
How does transport distance and energy affect particle size?
as the sediments moves, its characteristics change as it is physically broken down or chemically altered. The lower the energy of the depositional environment, the smaller the grain size of the clastic sedimentary rock
What are the three key types of sedimentary rocks and how do they differ? *
chemical, clastic and organic sedimentary rocks. Chemical sedimentary rocks occur when components of water evaporate and previously dissolved minerals are left behind. Clastic sedimentary rocks occur when there is buildup of tiny pieces of broken rocks (clastics). Organic sedimentary rocks occur as a result of the accumulation of any form of animal or plant remains like bones.
How are sediments transported?
erosion, water, wind and ice
